Installation of Flash Plugin - Debian
Open a terminal and edit the file /etc/apt/sources.list using a text editor and make sure following line exists:
deb ftp://ftp.debian.org/debian stable main contrib non-free
Save and close the file. Type the following command:
$ sudo apt-get update
Next, type the following apt-get command to install flash player plugin:
$ sudo apt-get install flashplugin-nonfree